Five airliners were involved in frightening midair “near-misses” in the New York area last month, The Post has learned.

The Federal Aviation Administration is investigating the potentially disastrous near-collisions, which were reported by the pilots.

The frightening spike in near-misses – there were only three in the area in 2006 – comes after two near-collisions above Kennedy Airport in January and February.

“Air travelers should be seriously concerned about their safety,” said Phil Barbarello of the air-traffic controllers union, who wants more controllers hired.

“The margin of safety is as low as I have ever seen, and I’ve been with the agency [FAA] for 23 years.”

Rep. Jerrold Nadler (D-Manhattan) agreed.

“This represents an unacceptable risk to the safety of air passengers and people on the ground,” he said, adding that he didn’t know “whether these near-misses are the cause of too many planes in the sky or overworked and understaffed air traffic controllers.”

The definition of a near-miss is two planes flying less than 500 feet apart. They are supposed to be kept 3 miles apart horizontally and 1,000 feet vertically.

Pilots report the incidents for investigation by the FAA. In two of the May cases involving JetBlue aircraft, the airline disputed its pilots.

The FAA confirmed there has been a spike in near-collisions but said no trends can be read into the numbers yet and denied there was a staffing problem with air-traffic controllers.

The most recent near-collision in the New York region was on May 21.

Continental Airlines Flight 466, a Boeing 757, was at 6,000 feet heading into Newark Airport when it had a close encounter with an unidentified aircraft.

The jet’s Terminal Collision Avoidance System sounded the alarm, and the pilots “took evasive action and descended,” according to an airport source.

“Our pilots receive extensive training to immediately respond to this type of event. The TCAS system did exactly what is was designed to do,” said Continental spokeswoman Julie King, who confirmed the near-miss.

The two planes came within 200 feet vertically and 1½ miles horizontally, according to the pilots’ report.

Another harrowing incident occurred at Kennedy Airport on May 17, when Chicago-bound American Eagle Flight 4392 was taking off. That plane, an Embraer 145 carrying 36 passengers, came within 200 feet of a helicopter that was taking off.

American Eagle spokeswoman Andrea Huguely said the passengers were not in danger.

“There was no need for our pilots to take any evasive maneuvering,” Huguely said.